Darth Qalar, a Dark Lord of the Sith of either Human or Sith pureblood heritage, held a position on the reconstituted Sith Empire's governing Dark Council circa 4043 BBY. Qalar engaged in a violent Kaggath, a traditional Sith duel, against fellow Dark Council member Darth Victun, resulting in the destruction of the Imperial Citadel located on Dromund Kaas, the Empire's capital planet. After Qalar and Victun declared a stalemate, the remaining Dark Council members swiftly executed them both. The possessions of the deceased Councilors were then used to rebuild the Citadel, and their respective family lines were eradicated.
The initial mention of Darth Qalar occurred within the Codex entry pertaining to the Imperial Citadel in the 2011 BioWare video game, Star Wars: The Old Republic. However, the Sith's designation remained undisclosed until the publication of the game's accompanying Encyclopedia.